Why do fish jump out of the water?

In this article, we will answer the question “Why do fish jump out of the water?” and learn which fish can jump out of the water.

Why do fish jump out of the water?

Fish tend to jump out of the water for a variety of reasons, the most common is when the fish are hunting or being chased. They also can jump to overpast an obstacle, if spooked and to move around. Thus, the main reasons that fish jumps are:

–       Prey capture;

–       Escaping from predators;

–       Overpassing obstacles;

–       Moving around;

–       Sexual behaviours;

–       Removing parasites;

–       When spooked.

Prey capture

Jumping can be a good strategy to capture prey. This is the case of carnivorous fish, whose diet is based on insects, birds, frogs, and other larger animals in the case of large sharks. They can jump out of the water to capture their food. It can be prey that lay on the surface or in the water column or animals that fly close to the surface. 

As a jumping technique, they curl their body to form a C-shape and paddle with the fins to reach the desired high speed. This strategy allows them to generate waves to distract the predator and to jump further ahead. 

Escaping from predators

Jumping is a good defence mechanism, as the fish being hunted can temporarily escape its predator and confuse it. This increases the survival chances because the predator will not see where the fish went nor be able to predict where it will land.

Overpassing obstacles

Some fish species leap out of the water as a manner to overpast an obstacle. If there is a structure, rock, or step on the stream, they can jump over it. If the current is too strong that a fish cannot beat it, they can also jump as a locomotion strategy to overpass this unfavourable condition.

Moving around

During the dry season, some river streams and ponds may become very poor in resources and may even end up dry. Thus, few fish species can jump out of the water to move around, as in an attempt of finding another safe and wet spot. They can use their fins as locomoting appendages. 

Another reason why some fish species move around by jumping is the poor water quality. Insufficient oxygen, high concentration of ammonia, nitrites and nitrates.

Sexual behaviours

Some scientists believe that jumping may be related to dating. As a strategy to seduce the opposite sex and can be used as an indicator of health status or showing off to attract mates. In this case, sexual selection takes place.

Removing parasites

Another theory is that jumping out of the water can be used to get rid of parasites. Some parasites can live attached to the skin of the fish. Thus, when the fish jumps and falls back into the water the impact displaces the parasites, usually removing them instantly.

When spooked

Some fish groups can behave differently when spooked. The main instrument that can spook the fish is fishing boats’ engines. When spooked, some fish species may jump out of the water in an escape attempt. However, this can be very dangerous to humans. In the case of big fish, they can cause injuries.

Jumping fish

Below are some fish groups, or species that perform jumps due to different reasons and their strategies to jump out of the water.

Salmon

The famous Salmon run up the river is a behaviour that typically requires the fish to jump out of the water at some point. This behaviour is related to their breeding period. 

They need to get up on the river to spawn, completing their life cycle. In some areas where there are waterfalls or too strong currents, it is common to observe salmon in an attempt to overpass the obstacles.

The technique used to jump is similar to other fish that also jump out of the water, although for other reasons. They have a jumping technique that allows them to perform very high jumps. They curl their body into an S-shape before quickly straightening and pushing their body into the air.

Sharks

Some fish species are known to be ferocious hunters, as the Great shark. Who has ever never seen a video of sharks jumping out of the water to capture seals?

Arowana

Arowana (Scleropages formosus) jumps out of the water to capture insects and small birds. The basis of their diet are animals that can be captured right above the surface. It has a jumping technique that allows him to perform very high jumps, they curl into an S shape before quickly straightening and pushing his body into the air. 

Flying fish

There are some species known as flying fish (Exocoetidae) that can glide when they are out of the water. Flying fish are small marine fish, no longer than 45 centimetres. They are usually chased by deep water sea species, such as :

–       Marlin;

–       Tuna;

–       Mackerel;

–       Swordfish.

As soon as they jump out of the water, they open their fins that acts similarly to wings and manage to glide for a maximum of 180 meters. 

Mackerel

There are registers of people getting hurt due to spooked Mackerels. They can understand that fishing boat noises are a threat and try to escape jumping. However, due to their usual size and morphology, they can become very harmful. A woman had her throat sliced due to a spooked one-metre-long 22 kilograms mackerel.

Tank fish jumping

One very common situation among aquarists is fish jumping out of the aquarium. This can occur for many reasons:

–       Mimicking natural behaviours;

–       Low oxygen amounts;

–       Dirty water;

–       Wrong water temperature;

–       Overpopulation;

–       Parasites infestation.

Mimicking natural behaviours

Some species practise jumps as their natural instinctive behaviours. If they typically jump out of the water in the wild, they will probably practice jumping out of the tank.

Low oxygen amounts

This is the most common condition that provokes a fish to jump out of the water tank. When the water contains very low amounts of dissolved oxygen, the fish can jump in an attempt of finding a well-oxygenated environment.

The water of a tank can become poor in oxygen due to:

–       Overpopulation of the tank. Thus, fish would compete for oxygen. Reducing the tank population or upgrading to a larger tank would help to avoid jumping fish;

–       Algae can also be competitors by oxygens amounts. Consider reducing the algae quantity if that is your situation.;

There are very clear ways to detect if your tank is becoming poor in oxygen. If your fish begin to spend a lot of time at the water surface or breathing quickly and heavily means that your tank water may be low in dissolved oxygen.

Dirty water

In dirty water tanks, the ammonia, nitrites, and nitrates concentrations can become toxic to the fish. Thus, the fish can try to escape these conditions in an attempt of finding a more ideal environment to live in.

In this case, the way you can make sure your fish have good water conditions is to use chemical test kits. The tank water should not contain any ammonia and nitrites quantity. Nitrates do not need to be zero, although, very close to it. These compounds are formed due to waste accumulation in the water. To prevent the water to get dirty, it is recommended to have a good filter, a vacuuming routine with a water changes program.

Wrong water temperature

If you opt for having tropical fish, make sure to have a nice heating system. Wrong temperatures or temperature fluctuation may cause fish jumping. 

This problem can easily be solved by having a good heater with a thermostat and thermometer. Make sure to learn your fish biology and needs. In addition, make sure that all of the fish in the tank require and stand in the same temperature range.

Overpopulation

If you have too many fish in your tank and the fish can start to jump out of the water, that probably means that you need a larger tank. Fish in overcrowded tanks can also become more aggressive or be hurt. 

To avoid overpopulating, understanding the fish species characteristics is very important. If your fish species are known to be aggressive and territorial, you should provide a tank with plenty of space for them to establish their territories, and with hiding spots. Also, consider having an upgrade to a larger tank. This can also help you on reducing fish jumping out of your tank. 

Parasite infestation

Similarly to the natural environment, if your fish are suffering from parasite infestation, they will try to find a manner to remove the parasites from their bodies. Thus, jumping behaviours can be very common in these situations. 

Parasites that provoke the fish to rub and scratch on rocks and tanks structures can also provoke fish jumping. 

A good fish examination can reveal if there is any type of parasite infestation on your tank. If you have, taking the fish to a veterinarian and improving the water conditions may help you to fight these organisms.

Conclusion 

In this article, we answered the question “Why do fish jump out of the water?” and learnt more about jumping fish and their reasons to jump out of the water.

If you have any thoughts or doubts, feel free to drop us in a comment below!

Frequently Asked Questions (FAQs): Why do fish jump out of the water?

What does it mean when fish are jumping?

Fish jumping can mean many things, from feeding to escaping from predators or sexual behaviours. The right answer will depend on the fish species and its biology.

What fish jumps the most?

Mako sharks are the fish that jumps the highest. They can jump up to 9 metres above the water surface.

Can a shark jump? 

Yes, the sharks can jump. Sharks jump on average up to 3 metres above the water surface. However, some species jump higher than this mark. The Great White Shark can jump higher than 5 metres and the Mako, above 9 metres, for example.

Can Megalodon jump?

Yes, Megalodon could jump. Although they are extinct, the megalodon could jump up to 3.5 metres out of the water.

How high can a dolphin jump?

Although dolphins are not fish, they can jump on average 8 metres above the water surface. However, some dolphins species can reach up to 12 metres above the surface of the water

Why do my fish jump out of the tank?

Fish in a tank may jump out of the water for many reasons. They are poor oxygenations, overpopulation, wrong water temperature, poor water quality, and parasite infestation.

References 

Why Do Fish Jump Out Of Water: All The Answers. 2021. https://www.aquariadise.com/why-do-fish-jump-out-of-water/

7 Reasons Why do Fish Jump Put of the Water. https://www.slo-fishing.si/fishing-for-beginners/315-why-do-fish-jump-out-of-the-water